Hobson's Choice

A Hobson's choice is a free choice in which only one option is offered. As a person may refuse to take that option, the choice is therefore between taking the option or not; "take it or leave it".

There is no fear but the fear of hunger. Mosquito nets are widely considered a magic bullet against malaria — one of the cheapest and most effective ways to stop a disease that kills at least half a million Africans each year. An insecticide-treated mosquito net, hung over a bed, is the front line in the battle against malaria. It’s also the perfect mosquito-killing machine. The gauzy mesh allows the carbon dioxide that people exhale to flow out, which attracts mosquitoes. But as they swarm in, their cuticles touch the insecticide on the net’s surface, poisoning their nervous systems and shutting down their microscopic hearts. But many are not using their mosquito nets as global health experts have intended. Across Africa, from the mud flats of Nigeria to the coral reefs off Mozambique, mosquito-net fishing is a growing problem, an unintended consequence of one of the biggest and most celebrated public health campaigns in recent years.

Isabel Marques da Silva, a marine biologist at Universidade Lúrio in Mozambique explained “That’s why the incidence for malaria here is so high. The people don’t use the mosquito nets for mosquitoes. They use them to fish.”

“I know it’s not right,” Mr. Ndefi said, “but without these nets, we wouldn’t eat.”

“It’s simple economics,” said Carl Huchzermeyer, a fisheries manager for African Parks, a conservation organization in Bangweulu. “You could spend two days making a basket out of reeds, or just use a mosquito net.”

Scientists now worry about the collateral damage: Africa’s fish. But the unsparing mesh, with holes smaller than mosquitoes, traps much more life than traditional fishing nets do. The Malagasy word for these nets is “ramikaoko,” or the thing that takes all things together. A “real” net costs about $50, an enormous expense in a place where many people survive on a few dollars a day. Scientists say that could imperil already stressed fish populations, a critical food source for millions of the world’s poorest people. Many of these insecticide-treated nets are dragged through the same lakes and rivers people drink from, raising concerns about toxins. One of the most common insecticides used by the mosquito net industry is permethrin, which the United States Environmental Protection Agency says is “likely to be carcinogenic to humans” when consumed orally. The E.P.A. also says permethrin is “highly toxic” to fish. Most scientists say the risks to people are minimal, because the dosages are relatively low and humans metabolize permethrin quickly. But with coldblooded animals, it’s a different story. In many places, fish are dried for hours in direct sunlight on treated mosquito nets. Direct sunlight can break down the insecticide coating. Anthony Hay, an associate professor of environmental toxicology at Cornell University, said fish could absorb some of the toxins, leaving people to ingest them when they eat the fish. “We think we have a solution to everybody’s problems, and here’s an example of where we’re creating a new problem.”

“If you’re using freshly treated nets in a smallish stream or a bay in the lake, it’s quite likely you’re going to kill fish you don’t intend to kill,” said Dan Strickman, a senior program officer for the Bill and Melinda Gates Foundation, which has invested heavily in malaria research and development. “That’s definitely an environmental hazard.

Recent hydroacoustic surveys show that Zambia’s fish populations are dwindling. Harris Phiri, a Zambian fisheries official, blamed deforestation, rapid population growth and the widespread use of mosquito nets.

“They are catching very small fish that haven’t matured,” Mr. Phiri said. “The stocks won’t be able to grow.”

People fishing with mosquito nets tend to be those without boats or even tackle, often women and children, the most dispossessed. They work from shore, tugging the nets through shallow waters, precisely where many species spawn, creating another potential problem: the slow, steady destruction of sensitive aquatic breeding grounds.

Jeppe Kolding, a Danish fisheries ecologist, has challenged the conventional wisdom. He advocates a “balanced harvest” approach that calls for catching more juvenile fish and sparing some of the adults, arguing that mosquito-net fishing may not harm fish stocks as much as widely believed.  “Fish are more like plants than other animals,” he said, “in that they disperse millions of seeds.” But even he acknowledges that, for fishing purposes, it would be much better if the nets used were not treated with toxic chemicals.

Madagascar’s industrial shrimp catch plummeted to 3,143 tons in 2010 from 8,652 tons in 2002. Madagascar recently banned the use of mosquito nets at Antongil Bay, a crucial shrimping area.

Big companies like BASF, Bayer and Sumitomo Chemical design the nets. They are manufactured at about $3 apiece, many in China and Vietnam, shipped in steel containers to Africa, trucked to villages by aid agencies, and handed out by local ministries of health, usually gratis. The World Health Organization says the nets are a primary reason malaria death rates in Africa have been cut in half since 2000. But at the end of the line, in poor areas where little goes to waste, mosquito nets become many other things: soccer balls and chicken coops, bridal veils and funeral shrouds. Mosquito nets are literally part of the fabric of a community.

People know all too well the dangers of malaria yet also know loved ones will not last long without food.